ORP Ślązak (1954)

	Polish M-class submarines in port
History
Soviet Union
Name	M-270
Builder	Sudomekh Shipyard, Leningrad
Laid down	December 23, 1949
Launched	April 24, 1950
Commissioned	July 29, 1950
Decommissioned	December 30, 1954
Poland
Name	ORP Ślązak
Commissioned	October 18, 1954
Decommissioned	October 20, 1965
Fate	sunk as a target ship
General characteristics
Class & type	M-class submarine
Type	M-XV
Displacement	surfaced: 283 t (279 long tons); submerged: 353 t (347 long tons);
Length	49.5 m (162 ft 5 in)
Beam	4.4 m (14 ft 5 in)
Draft	2.6–2.8 m (8 ft 6 in – 9 ft 2 in)
Propulsion	2 diesel engines, 441 kW (591 hp) each; 2 electric motors, 160 kW (210 hp) each; 2 propellers;
Speed	surfaced: 15.7 kn (29.1 km/h; 18.1 mph); submerged: 7.8 kn (14.4 km/h; 9.0 mph);
Range	surfaced: 4,500 nmi (8,300 km; 5,200 mi) at 8 kn (15 km/h; 9.2 mph); submerged: 85 nmi (157 km; 98 mi) at 2.9 kn (5.4 km/h; 3.3 mph);
Complement	31
Armament	1 universal gun, 45 mm (1.8 in) caliber; 4 torpedoes; torpedo tubes: 4 × 533 mm (21.0 in);

ORP Ślązak was a Polish Cold War-era submarine, originally the Soviet M-270, one of six M-XV-series (Project 96) vessels of the M type acquired by Poland. It displaced 283 tonnes (279 long tons) surfaced and 353 t (347 long tons) submerged, with its primary armament consisting of four 533-millimetre (21.0 in) torpedoes launched from four internal torpedo tubes. The submarine achieved a surface speed exceeding 15 knots (28 km/h; 17 mph), with a range of 4,500 nautical miles (8,300 km; 5,200 mi) at 8 knots (15 km/h; 9.2 mph).

Launched on 24 April 1950 at the Sudomekh Shipyard in Leningrad, it entered service with the Soviet Navy on 29 July 1950, assigned to the Baltic Fleet. In 1954, Poland leased the vessel, commissioning it into the Polish Navy on 18 October 1954. Designated with pennant numbers M-103, P-103, and later 304, it served extensively until decommissioned on 20 October 1965 and was subsequently sunk as a target ship in the Bay of Puck.